The onset of senescence is a significant problem in the flower industry. Although the useful lifetime of cut flowers can be extended by refrigeration and by use of certain chemical preservatives, the fact that many flower varieties are shipped as cut flowers over long distances has provided strong motivation to develop additional means to extend flower bloom life.
Although placing cut flowers in a solution of water affords some measure of preservation by keeping the flowers hydrated, chemical preservatives are often added to such a solution to extend bloom life. Among the chemical preservatives currently in use are nutrient supplements, which may include a sugar component as well as an acidic agent to maintain the pH of the solution at about 4. Nutrient supplements of this type are commercially available, and include "CRYSAL" and "FLORALIFE", for example.
Other chemical preservatives currently in use work by interfering with the action of ethylene, which plays a central role in senescence. Such preservatives include silver thiosulfate (STS), 2,5-norbornadiene, aminooxyacetic acid (AOA), and aminoethyoxyvinylglycine (AVG). Silver thiosulfate and 2,5-norbornadiene act by antagonistically blocking ethylene action. Aminooxyacetic acid and aminoethyoxyvinylglycine, on the other hand, act by inhibiting ethylene synthesis. Although these agents have been shown to be effective floral preservatives (Reid et al., 1991; Beyer, 1976; Sisler, 1983; Fujino et al., 1981; Baker et al., 1977) and, moreover, are sometimes effective when used in combination with a nutrient supplement such as mentioned above, their toxicity and expense present significant drawbacks. Accordingly, new post-harvest floral preservatives that are non-toxic and environmentally safe have been sought.